Cement lithographic stone.



No. 878,822. v PATENTED FEB. 4; 1908. H. WAGNER.

GEMENTED LITHOGRAPHIG STONE.

APPLICATION FILED FEB. 23, 1904.

a a la 'a a W I MM w @wmh z mm UNITED STATES PATENT OFFICE.

HUBERT WAGNER, OF MUNICH, GERMANY, ASSIGNOR TO OHARLOTTENBURGER FARE-WERKE AKTIENGESELLSOHAFT, OF OHARLOTTENBURG, PRUSSIA, GERMANY.

CEMENTED LITHOGRAPI-IIG STONE.

Specification of Letters Patent.

anissnan Patented Feb. 4, 1908.

To all whom it may concern:

Be it known that I, HUBERT WAGNER, a subject of the King of Bavaria,residing at Munich, N., Bavaria, Germany, have invented certain new anduseful Improvements in Cemented Lithographic Stone, of which thefollowing is a specification.

The object of the present invention is to provide lithographic stonecomposed of sev eral separate pieces cemented by such means that thecomposite surface answers the many requirements of every printingprocess and possesses the requisite strength in the same degree as thesurface of a single stone, and that the cementing produces noirregularities or flaws.

The object of the improvement is in the first place to allow ofproducing at very low cost, by the interconnection of small andinexpensive stones, large stones of sizes which in combination with therequisite quality for printing and complete freedom from flawsthroughout their surfaces, are rarely found in the quarries and aretherefore very exensive in a natural state; by carefully seecting theseparate small stones the composite surface may even be of betterquality than the surface of a single large stone of the natural size.Very large plates and blocks of stone such as would be required for theroduction of the larger rollers for rotary ithographie printing are notfound at all in the quarries, or are at least extremely rare.

The printing surface of a composite plate or roller, produced by joiningtogether the edges of separate parts, must answer the same numerous andvarious requirements as a plate consisting of a single naturalhomogeneous piece The composite plate or roller must be very strong, inorder to withstand the frequently very high pressure exerted thereon.Notwithstanding the great strength with which the separate pieces mustbe connected by the cemented parts, that is to say, at the joints orseams in the comosite surface, the said joints must beani mitely fine,so as to be practically invis1ble to the naked eye. At these parts ofthe joints covered by the design the color must adhere in the samedegree as to the stone. On the other hand, no color must adhere to thejoints where the printing surface is to remain free from color. Duringthe printing, colors must be delivered to the paper by the roller asreadily and exactly as by the stone itself. It must be possible to treatthe composite surface with caustic as uniformly as the surface of asingle stone, without acid or water eating into the joints. Finally itmust be possible to polish the entire plate with complete uniformitywithout producing lesions or cracks at the joints. As will be seen, therequirements are many and various. The composition or building up of aplate or roller from separate pieces, to possess a uniform surface,having with regard to the requirements stated, entirely the samephysiological properties as a single homo eneous piece of stone, iseffected in the fdllowing manner, reference being made to theaccompanying drawing in which Figure 1 is a plan and Fig. 2 an edge viewof a flat stone composed of four parts. Fig. 3 is an elevation and Fig.4 an end view of a roller composed of three parts meeting on transverseplanes. Fig. 5 is an elevation and Fig. 6 an end view of a roller com)osed of four parts meeting on longitudinal p anes.

The edges of the separate stones a are smoothly polished so that thepieces fit well together. .lioughening of the edges is unnecessary. Theedges to be joined together are then coated with a cement b composed of1 part shellac dissolved in 3 parts pure alcohol and 1 part sulfuricether, in some cases with the addition of approximately 3; partpulverized stone. These mixing proportions can, however, be varied, andthe addition of stone can be dispensed with, with some kinds of stone tobe treated. After being placed together the stones are subjected tolateral compression in a suitable press until the mass has completelyhardened, and the surface of the composite plate is then suitablypolished.

Since the invention allows of producing rollers or cylinders as well asflat plates it thereby opens up another field of industry. Quiterecently the inventor has started entirely new branches of industry (forinstance, lithographic wall-paper printing and the like) by using,instead of the piano-lithographic printing of single sheets rotaryprinting of paper in web, by means of cylinders of lithographic stone.The construction of rollers, more particularly of rollers with perfectsurfaces, with the limited material supplied by the generally flatstrata of the 5 seams in the colored parts of the plate or A quarries,was even more difficult than obtaining large flat plates. It has alsobeen found necessary, in recent times, to have rollers of considerablylarge diameter in order to perform rotary printing with success, sinceonly a restricted utilization of that method of printing is possiblewith rollers which are at most 25 centimeters in diameter. Byconstructing rollers of separate segments joined together, rollers ofvery much larger diameter can be obtained, and by this means the outputcan be largely increased and wider scope obtained in the type ofrinting.

li am aware that it has been previously proposed to form flat stones outof several pieces cemented together, but the methods hitherto proposedare insuflicient to produce such a stone suitable for use.

I do not claim broadly thecementing of lithographic stones but only suchas are powdered lithographic stone.

cemented by use of a cement having the characteristics quoted in myclaims.

I therefore claim:

1. A lithographic late or roller, comprising a plurality of litliographic stones united together by a mixture of shellac cement and 2.The combination in a lithographic plate or roller of separate pieces oflithographic stone and binding agent substantially consisting of shellacdissolved in alcohol and sulfuric ether and including powderedlithographic stone.

In Witness whereof I have signed this specification in the presence oftwo Witnesses.

HUBERT WAGNER.

Witnesses MAX GIEGEL, MATH. HELDE.

